Years of playing first-person shooters has apparently made me immune from camera-induced nausea. Pretentious movie critics of the 80s made similar remarks to the warning above about certain segments of Highlander, which I saw opening week while suffering from a splitting headache, and having set my stomach on edge already by taking too many Nuprin. (Remember Nuprin? Little, yellow, different?) Despite my condition, I didn't notice anything amiss with the camera action, even in the wacky opening helicopter-around-the-auditorium scene. And the same with Cloverfield. I commented on seeing the preview, and I've seen in countless reviews, blogs, and forum posts, that Cloverfield was "Godzilla meets Blair Witch". In fact, it was less like Blair Witch in camera style, more like the Cops TV show. As with Highlander, I didn't find the jerkiness of Cloverfield the least bit upsetting; the camera operator did a good job of keeping what we needed to see in view.
The movie content, however, that was upsetting - psychologically, not in a pretentious movie critic way. I loved it. It was scary. The effect of running around on the ground with a few survivors trying to accomplish a secondary goal while avoiding the monster played off a lot like a zombie movie. So, instead of Godzilla meets Blair Witch, let's call it Cops meets 28 Days Later.
My recommendation: Don't read any spoilers, and go see it. Take a Dramamine if you're a big wuss, but go see it. If you liked Children of Men, or Rob Zombie's Halloween, or Zack Snyder's Dawn of the Dead, or Alien - go see it.